Fuel feeder and controller.



C K. LASSITER.

FUEL FEEDER AND CONTROLLER. APPLICATION FILED DEC. 9, 1914.

Patented D00.1. J16.

4 SHEETS-SH I.

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C K. LASSITER.

FUEL FEEDER AND CONTROLLER.

APPLICAT |0N FILED DEC. 9. 1914.

1L 2@9.,59?. Patented Dec. 19, 1916.

4 SHEETS-SHEET Z- I I 60mm Razz/5K. 13mm Q C K. LASSITERf FUELTEEDER ANDCONTROLLER. APPLICATION man 0509,1914.

13%,597. Patented Dec. 19,1916.

4 SHEETS-SHEET 3.

Elvweniioz LL Q 3 GICO'LMM C K. LASSITER.

FUEL FEEDER AND CONTROLLER. APPLICATION FILED DEC. 9, l9l4.

1 99 59? Patented Dec. 19, 1916.

4- SHEETS-SHEET 4.

@muamtor 5% a wm m 1 spective view of the mars sraa ns raran one.

' COLUMBUS K. LASSITER, OF RICHMOND, VIRGINIA.

FUEL FEEDER AND coNrRoLL R.

To all whom it may concern:

Be it known that I, CoLUMBUs K. LASSI- TER, a citizen of the UnitedStates, residing at Richmond, in the county of Henrico and State ofVirginia, have invented new and useful Improvements in Fuel FeedersandControllers, of which the following is aand simplicity of construction,economy in the use of fuel, capacity to vary the supply of fuel asdesired, and proper proportioning of fuel and air supply and,coordination in regulating the blast, fuel feed and velocity of the fuelmixture.

Other and more specific objects and advantages of the invention arehereinafter fully set forth.

In the accompanying drawing, showing one form of means for carrying myinvention into practical efi'ect, Figure 1 is a perspective view of myimproved fuel feeding and controlling apparatus as adapted for use inconjunction with a steam boiler furnace, the. latter being fragmentarilydisclosed. .Fig. 2 is a sectional perspective view of the feeder andblast and suction'chambers. Fig. 3 is a fragmentary bottom per dischargeportion of the feeder casing, showing the fuel feed valve in openposition. -Fig. 4 is a vertical longitudinal section through the feedingand mixing portions of the apparatus. Fig. 5 is a sectional plan view online 55 of Fig. 4.

- Fig. 6 is a vertical transverse section on the line 6-6 of Fig. 4.Fig.7 is a vertical longitudinal section through the fuel delivery orburner nozzle and showing the velocity regulator valve in closedposition.-

Referring to the drawings, 1 designates a .bin or hopper to which thepreviously dried and pulverized coal dust is supplied many I suitablemanner, and which communicates Specification of Letters Patent.

Patented Dec. in, rain.

Application filed December 9, 1914. Serial No. 876,320.

at its bottom through a conductor 1 with the inlet'2 of a feeder. Thisfeeder comprises a casing 3 formed with. a receiving chamber 4 andlongitudinal, parallel comp'artments o and 6 in which respectivelyoperate a feed screw 7 and a return screw 8.

The compartments 5 and 6 are in communication at their ends throughcross passages 9 and 10, so that the excess portion of the coal dustwhich is not discharged into the feed conduit from the compartment 5will pass to the compartment 6 through the channel 9 and thence returnby the action of the screw 8 and through the channel 10 to the screw 7for return to the chamber l, whence it passes again with accretions tothe compartment 5 for feed travel to the discharge outlet.

The feeder is designed to be continuously operated and to have aconstantly uniform or invariable feeding capacity, which is always ofthe maximum degree, so that a constantly uniform volume of fuel will bepresented at all times at the discharge outlet for supply to the feedconduit, thereby obviating any necessity of controlling the action ofthe feeder member per se, together with the objections incident thereto.These screws are provided at one end with intermeshing gears 11 and 12whereby they are adapted to be driven in unison, and at its opposite endthe screw 7 carries a pulley 13 or other means for receiving drivingpower from a motor or other suitable source, designed to operate thescrews constantly at uniform speeds. The compartment 5 communicates withthe chamber l at a point betweenits center and the passage 10 and-1sformed at its mouth with a cut-off flange or projection 14 extendinginto said chamher. about which flange the coal may bank to keep the coalat a substantially fixed outlet 15 formed inthe bottom of thecompartment 5. which outlet is of a' definite size and is controlled bya sliding feed regulating valve 16 movable in a guideway 17, and whichis connected at one end with a rack bar 18, the toothed portion of whichis exposed through slots 19 in the walls of the guideway and meshes witha gear segment 20 mounted upon a rock shaft 21, the construction beingsuch that the valve may be moved to bring more or less of a feed slot 22therein into registry with the outlet 15 to permit a. greater or lessamount of the coal dust to discharge. The intermediate portion of thefeed casing extends between and is suitably secured to the proxi mateportions of a blast chamber 23 and a suction or primary mixing chamber24, which chambers are in communication through a pair of parallelvertical blast passages 25 which are arranged on opposite sides of thatportion of the compartment 5 in which the outlet 15 is formed. Dependingfrom this compartment withinthe chamber 24 is a suction tube or nozzle26 which is provided at its upper end with a flange 27 suitably securedin position to support said tube, which forms with the bottom of thecompartment 5 a guide passage 17. The tube or nozzle 26 receives thecharge of fuel dropping thereinto through the valve slot 22 when thevalve is open and delivers such charge into the chamber 24, which isarranged at the upper end of a vertically disposed mi'xing tube orchamber 27, provided at its lower end with a horizontally extendingdelivery portion 28, through which the fuel is delivered to thecombustion chamber in the manner hereinafter described.

The blast chamber 23 communicates at its upper end with a low pressureair supply or blast pipe or tube 29, supplied with air from a fan orblower or other suitable source, the air being delivered for flowthrough the feed conduit formed by the elements 29, 23, 24 and--28 at aproper working pressure which is sufficient to supply the right amountof air to commingle with the dust in the tube.27 to form a combustiblecharge, and to deliver the charge at a uniform velocity into thecombustion chamber without, blowing the charge at high pressure andvelocity into the combustion chamber with its attendant objections. Thecolumns of air feeding downward through the passages 25 enter thetapering chamber 24 on oppwite sides of the tube 26 and meet immediatelybelow the lower delivery end of said tube, thus creating a suction andforming a partial vacuum in saidtube, by which the amount of fuelexposed for delivery at the opening 15 will be instantly drawn into thetube, whereby the accurate supply of a definite amount of fuel to thefeed conduit, proportionate to the efieotive transversely of said pipe.

t eater size of the slot or port 22, is insured. As this dust so drawninto the chamber 24 comes in contact with cross currents of air agitatedby the combination of the two currents of air traveling through therespective passages E In order to secure greater reliability and greatercfiiciency of control over the fuel mixture supplied to the combustionchamber, I provide at the delivery end of the feed column-a fuel anddelivery nozzle or burner 30, which extends into the combustion cham herthrough one of the walls 31 thereof. This nozzle is preferably ofrectangular form in cross section and has its upper wall preferablyinclined to form a hood 32 above the level ofthe upper wall of the pipe28,

and so as to provide a flaring passage for the discharge of the fuelmixture and to receive a velocity regulating valve or damper 33. Thisvalve comprises a disk or plate of proper form to snugly fit between thesides of the nozzle and mounted at its outer end upon a transverse rockshaft 34, whereby it is arranged to swing or tilt vertically todifferent positions. It is evident that by the useof this valve ordamper the size of the passage between the fuel feed conduit andentrance to the combustion chamber may be varied and regulated so as toproportionately regulate the velocity of the feeding stream of fuel,enabling the velocity to be kept uniform notwithstanding any variationsof working pressure according to the difierent conditions ofserviceunder which the furnace is being operated. ll also provide in theblast or air supply pipe 29 a blast regulating gate or valve 35 which ismounted to slide To the .rock shaft 34 of the valve 33 is attached anarm 36 carrying an adjustable weight 37 by which said valve is adaptedto be automatically opened by gravity, and attached to one end of thegate or valve 35'is a cord or cable 38 depending over a guide pulley 39and is also provided with an arm or handle 43 by.

which the shaft and gear may be operated to adjust said valve to closedposition. 0n the 7 shaft21 are pulleys 44 and 45 to which, are

respectively attached cords or cables 46 and 47, the cord 46 beingattached to an'actuating arm 48 on the shaft 34 and the cord or 0 cable47 being passed over a guide pulley 49 and connectedwith the valve 35 sothat the said valves may be simultaneously opened to opened or closed toproper degrees, it being noted that all three Valves 16, 33 and 35 areunited for simultaneous adjustment. In practice, I may connect the arm43 with the rod of a piston 51 movable in a cylinder 52 and which may beconnected with the steam generating space of a steam boiler, so that thepiston will be forced downward to greater or less degrees according tothe pressure of the steam, allowing the amount of fuel fed to thecombustion-chamber to be accurately regulated according to the degree ofthe boiler pressure. By this means, the supply of fuel may be entirelycut off when the boiler pressure reaches a maximum degree and may beregulated to control the I, temperature Within the combustion chamber toregulate the generation of the steam to a desired workin pressure withmaximum reliability and e ciency. It will, of course, be understood thatany equivalent means for operating the valve adjusting mechanism may beemployed in lieu of that shown, 'or the valve controlling mechanism maybe manually operable to regulate the supply.of fuel and air and thevelocity of flow of the mixture to the combustion chamber, accord ing tothe requirements.

It will be apparent from the foregoing de scription that in theoperation of my 1mproved fuel feeding and controlling system the feederworks at'the same capacity at all times, and at all times presents thesame amount of fuel at the outlet 15 for discharge into the mixing andsupply conduit, thus obviating the necessity of employing vari ablespeed motors or'other means for driving the feeder which requiresadjustment in order to regulate the feed action, thus avoiding the useof driving means which can not be regulated without trouble and labor orwith any degree of reliability and efliciency. It will also be seen thatby a certain and positive adjustment of the feed valve 16, the size ofthe fuel feed outlet is regulated to an exact degree according to theamount of fuel required, and that a regulated supply of fuel to themixing and feed conduit will be furnished, thus avoiding uncertaintiesand irregularities resulting from the fuel feed action of a blastemployed for this purpose. Furthermore, it will be seen that as the fuelpresented for discharge is positively drawn by suction into the feedconduit choking of the feeder can not occur, and that as impingingcurrents of air are encountered by the entering charge, which currentsproduce a tumbling body or volume of air, a thorough may be supplied inany suitable manner when deemed desirable. Another and materialadvantage of nay-invention is that the supply of fuel and supply of airare proportionately and coordinately governed,

and the velocity of the feeding mixture also governed proportionately tothe amount of fuel and air, thus insuring efficient ca1ibration oraccurate and proportionate regulation of the feed of fuel according tothe work to be performed or heat units furnished, the supply of theexact amount of air to form therewith the combustible mixture, and theregulation of the supply and velocity of the mixture according torichness and volume. Thus when the valve is set or adjusted to supply adetermined quantity of fuel within any given period of time, the deviceswhich control the admixture of air inproper proportion with the amountof fuel furnished and which control the velocity of feed of the fuelaccording to its amount and richness will be adjusted at the same time,thus insuring an absolutely efiicient coordination of all workingelements at different ranges of temperatures to be produced, governed orcontrolled, a practical impossibility where the working action of thefeeder is varied, or where the fuel, air supply and velocity are not,all controlled and governed coordinately.

" Fuel feed systems employing powdered coal have been heretofore usedwith the greatest efliciency in rotary cement kilns. As these kilns havea combustion chamber of great length, but a simple type of feedmechanism is necessary, as the range of travel of the fuel is sufiicientto secure combustion without'the necessity of regulating the mixture andsupply of coal and air with any great degree of accuracy. This is due tothe fact that the long range of travel of the fuel, which is of along-flame and slow-burning character, permits of the burning of the.fuel to a high degree. In the employment of feeder through the actionof a variable speed motor by which it is driven, but this isobjectionable for the reason that it is difficult and practicallyimpossible at times to secure perfect coerdination between the feederand the air supplying means, and to proportionately regulate thevelocity. If the amount of air supply is too large the efficiency of theform supply of fuel or to regulate the air in the hopper.

' portions can not be obtained.

blast to vary the amount of fuel supply with proper accuracy, and itoften found that with this system,-which employs feeding and returnscrews, that a portion of the high pressure air frequently escapesthrough the hopper by sweepage through the fuel unless a large quantityof fuel is constantly kept In one prior system ll am aware of, anattempt has been made to regulate the supply of air and fuel fordifferent working actions by the use of a feeder having a constantlyuniform feed action in connection with a dropper valve and a mixingchamber capable of being expanded and contracted in diameter inconformity with the degree of adjustment of the valve. to vary the fueland air feed supply, but this type of device has been found to beirregular and ineffective in action, owing to the construction and modeof air supplying means employed, to the use of obstructions in the feedconduit and to the practice of varying the size of the mixing chamber orconduit itself, which causes choking under many conditions. Moreover,this device does not provide any means for controlling the admission ofair to the air conduit, and accordingly proper. control of-the elementsof the combustible mixture in roper proy invention overcomes all ofthese objections and insures a more perfect and uniform feed of the fueland air, and 'other admixture, as well as their supply in variablequantities for sliderent conditions of service, according to the degreesof heat units to be furnished, and by the provision of means forregulating the admission of air as well as the admission of fuel, andalso the control of the velocity of the feed, a cofirdination of actionof the moose? delivery conduit, of a feeder for supplying the coal dustthereto, a valve for regulating the amount of fuel delivered by thefeeder to the conduit, a valve for regulating the admission of air tothe conduit, a valve in the conduit for governing the velocity of thedelivered fuel mixture, and means for simultaneously and cobrdi'natelyadjusting said valves.

2. In a fuel feeding apparatus .for coal dust, the combination of amixing and delivery conduit, a feeder having an outlet in communicationwith the conduit, a valve controlling said outlet, a valve forcontrolling the supply of air to the conduit, a valve for regulating thedelivery velocity of the mixture, and automatic means for simultaneouslyand coiirdinately adjusting said valves.

3. In a fuel feeding apparatus for coal dust, the combination of amixing and delivery conduit, a valve controlling the supply of airthereto, a feeder having a delivery opening communicating with theconduit, and means cooperating with said opening for drawing the fuelcharged by suction into the conduit, a valve controlling said opening, avalve for regulating the delivery velocity of the fuel mixture, andmeans for simultaneously and coordinately adjusting said valves.

4. In a fuel feeding apparatus for coal dust, the combination with afuel feeder, of means for discharging predetermined quantities of fueltherefrom, means for supply ing air for admixture with the fuel charge,means for governing the delivery velocity of the fuel mixture, and meansfor simultaneously and coordinately governing the fuel discharge, airsupplying and velocity regulating means.

5. In a fuel feeding apparatus for coal tion to draw the fuel chargesinto the con duit, a valve for controlling the inlet of air, a valve inthe delivery portion of the con duit for controlling the deliveryvelocity of the fuel mixture, and means for'simultaneously andcoordinately adjusting said valves. 1 v

6. In a feeding apparatus for coal dust, the combination of a conduithaving an air inlet end and a fuel delivery end, an air admission valveat the air delivery end, a

eluding means for producing a suction acduit and innate? velocitycontrolling valve at the fuel delivery end, a feeder having a constantlyuniform feeding action and provided with an outlet communicating withthe conduit between said air inlet and velocity controlling valves, saidoutlet being arranged to form passages for the flow of air, a valvecontrolling said'fuel discharge outlet, and means for simultaneously andcoordinately adjusting the several valves to proportionately vary theadmission of air and feed of fuel and control the velocity of the fuelmixture.

7. In a feeding apparatus for coal dust, the combination of a feedconduit having an air inlet at one end and a fuel discharge outlet atitsopposite end, a valve controlling the admission of air to saidconduit, a valve within the discharge portion of the conduit forcontrolling the velocity of the fuel mixture, a fuel feeder having aconstantly uniform feed capacity, said feeder being provided with anoutlet projecting into the conrovided with a suction discharge nozzle, auel feed valve controlling the dis- .charge of the fuel from the outletto said nozzle, and means for simultaneously and coordinatel adjustingthe air inlet, fuel velocity and fiiel discharge valves.

8. In a feeding apparatus for coal dust, the-combinationwith a deliveryconduit, of valve controlled means for feeding coal dust to saidconduit, valve controlled means for supplying air to the conduit inrearof the valve controlled fuel supplying means in the direction oftravel of the fuel mixture, a velocity regulating valve within thedelivery portionof the conduit, and means forusting said valvessimultaneously and coinate y for proportionately controlling theadmission of a1r, supply of powdered fuel and velocity of the mixture.

9. In a fuel feeding apparatus for coal ad r dust, the combination of asupply conduit,

means for feeding the fuel to said conduit, means for supplying a blastof air under low pressure to the conduit in rear of the fuel foradmixture with the fuel and travel therewith toward the delivery end ofthe conduit, and means regulable simultaneously and coordinately forgoverning the admission of fuel, regulating the supply of air to theconduit in proportion to the amount of fuel supply, and governingdischarge of the fuel mixture. 7

10. In a' feeding apparatus for coal dust,

1 the combination of a supply conduit, an air inlet valve governing thesupply of air to the conduit, a velocity control ing valve at thedelivery end of the conduit, a feeder having a constantly uniformfeeding action, and provided with an outlet openmg into the conduit at apoint between said valves, for the supply of the fuel to the interior ofthe conduit in the ath of the flowing air,

a valve for controlling the feed of the fuel the velocity of,

through said outlet, and means for cooperatively adjusting said valvessimultaneously.

In an apparatus for feeding pulverized fuel, the combination, with acombustion chamber, of means for feeding thereto a flowing column of afuel mixture of air and pulverized fuel commingled in .constantly fixedrelative proportions and traveling. at a constantly fixed velocity, andmeans for varying the volume of the fuel mixture fed to the combustionchamber without varying the relative proportions of" the air and fuelconstituents of said mixture i and also without varying the velocity offormed in the conduit to draw the fuel chargesinto the conduit throughthe nozzle by suction.

13. In a feeding apparatus for coal dust, the combination of a feedconduit, means for admitting air thereto, means for admitting fuelthereto, means for govering the velocity of the mixture of fuel and air,and means for governing the action of the aforesaid means in unison.

14. In a feeding apparatus for coal dust, a vertically disposed airconduit, a horizontally disposed feeder having an outlet in its bottomcommunicating with said conduit, and arranged to separate said conduitinto a plurality of passages, a suction nozzle communicating with saidoutlet and depending vertically into theconduit, and means 1forregulating the eflective size of the out- 15. In a feed apparatus forcoal dust, a vertically disposed mixing chamber having a horizontaLdelivery portion, an air supply pipe communicating with the upper end ofsaid chamber, a feeder interposed between the chambers and provided withair passages and a discharge outlet, a suction nozzle depending fromsaid outlet into the mixing chamber, a valve inthe air Valve controllingsaid'outlet, a; valve ln the delivery portion of the mixing chamber forcontrolling the delivery velocity'of the fuel mixture, and means forsimultaneously and coordinately adjusting said valves.

16. In a feeding apparatus for coal dust, an air supply, mixing anddelivery conduit, a feeder having an outlet communicating with saidconduit, a valve for controlling pp y p said outlet, a valve forcontrolling the admission of air, a valve for controlling the deliveryvelocity of the fuel mixture, means for adjusting the fuel feedcontrolling valve to regulate the supply of the coal dust, and

means governed thereby for simultaneously and coordinately adjusting theair admission and velocity regulating valves.

17. In a feeding apparatus for coal dust,

the combination with a feeder, for supplying coal dust, of valvecontrolled means for regulating the discharge of the fuel into the feedline, valve controlled means for supplying air for admixture with thesupplied fuel, valve controlled means for regulating the deliveryvelocity of the mixture, and means for simultaneously and coordinatelyadjusting the respective valves. 18. In a feeding apparatus for coaldust, the combination with a feeder, of a mixing conduit having avertically disposed mixing chamber and a horizontally disposed deliveryportion, means for regulatingthe admission of air to the mixing chamber,and means for regulating the feed of coal dust to the mixing chamber,means in the horizontal delivery portion of the mixing chamber forregulatlng the delivery velocity of the mixture without varying the areaof the mixing chamber, and means for adjusting all of the aforesaidmeans in unison.

19. In a feeding apparatus for coal dust, the combination of a feederhaving a'constantly uniform feed capacity, an air conduit incommunication with the feeder, for the delivery of the fuel to acombustion chamber, and means for simultaneously and coordinatelycontrolling the supply of fuel from the feeder to the conduit, theadmission 4 of atmospheric air to the conduit and the velocity of thedischarge of the fuel mixture of coal and air from the conduit.

20. In a feeding apparatus for coal dust, the combination of a feedconduit, means for supplying air under low pressure to the conduit,means for supplying powdered fuel to the conduit in 'a' directionparallel with the direction of flow of the air column, and means forcooperatively controlling the air and fuel supply in proper proportionsand controlling the velocity of the fuel mixture.

21. In a fuel feeding apparatus for coal dust, the combination of a feedconduit, means for supplying fuel to the conduit,

form with the powdered fuel a combustible mixture, and means forproducing cooperat mg variations in the supply of fuel and air "supplyand coordinately controlling thevelocity of the mixture.

'22. In a fuel feeding apparatus for coal dust, the combination with afeed conduit having inlet and delivery portions, a fuel feeddevicearranged at a pomt between said $5 portions and having a deliveryportion exmeans for supplying air to the conduit to tending laterallyinto the conduit and provided with a. discharge outlet for the pow- 23.In a feeding apparatus for coal dust, I

the combination of a feed conduit, a valve controlling the supply of airunder low pressure to the conduit, a feeder having a constantly uniformfeeding capacity and provided with an outlet within the conduit, adischarge nozzle communicating with said outlet and arranged todischarge the fuel in a path parallel with the direction of flow of thecurrent, a valve for controlling the velocity of the mixture, a valvecontrolling the supply of fuel from said outlet to the nozzle, and meansfor adjusting the respective valves in unison.

2a. In a fuel feeding a paratus for coal dust, the combination 0 a fuelconduit, means controlling the admission of air to the conduit, a feederhaving an outlet communicating with the conduit and operating to supplya constantly uniform amount of fuel to the outlet, means for governingthe discharge of the fuel through the outlet by suction in predeterminedamounts and in a direction parallel with the path of flow ofthe aircurrent, a valve for governing the velocity of the fuel mixture andmeans for con- I trolling the aforesaid controlling and governing meansfor proportionately regulating the admission of air and fuel and the ve-I locity of discharge of the mixture.

25. In a fuel feeding apparatus for coal dust, the combination with afeed conduit, of a feeder having a substantially uniformfeedingcapacity, a suction nozzle for discharging the fuel therefrominto the conduit, said nozzle being arranged to project the fuel dustinto the conduit parallel with and in the direction of the line of flowof the air current, valves for controlling the admission of air, fueland velocity of the mixture, and pressure controlled mechanism for'governing said valves.

26. In a dust, the combination of a fuel conduit, a fuel feeder, valvemechanism governing the supply of air and fuel to the conduit and thefeed velocity of the mixture, and pressure controlled means governingsaid valve mechanism. I a

27. In a fuel feeding a paratus for coal dust,- the combination 0 an airconduit, means. for admitting air thereto, means for supplying coal dustthereto to commingle fuel feeding apparatus for coal.

With the air to form a combustible mixture,

In testimony whereof I affix my signature means for controlling thevelocity of the in presence of two witnesses.

mixture, and means for governing the aforesaid means to proportionatelyvary the supply of air and fuel and govern the velocity of the mixtureaccordingly.

- COLUMBUS K. LASSITER. Witnesses:

H. B. HUNT, C. C. HiNEs.

